Composite materials such as carbon fiber reinforced polymers have long been used to create structural elements due to their low weight and high stiffness/strength to bending moments along the oblong fibers' orientation.
U.S. Pat. No. 5,413,060 to Quigley, incorporated herein by reference, describes using a fiber reinforced composite material to make a sail batten. The cross-sectional geometry of the batten changes from the proximal end of the batten located near the mast to the opposite distal end near the trailing edge of the sail in order to adjust the stiffness of the batten along its longitudinal length.
One problem with such prior battens is that although they may provide a superior response to dynamical longitudinal bending moments, they may not exhibit adequate strength and stiffness to dynamical torsional moments. This can be a problem when the cross-section of the batten is not angularly uniform and when the batten loosely engages the pocket in the sail. Relatively loose engagement is preferred in order to easily insert and remove the batten from the pocket. Further, due to unpredictabilities and inaccuracies in the shape of the pocket, often caused by lack of precision in manufacturing, and caused by wear on the sail, the batten may be subjected to various unplanned bending and torsional loads.
Therefore, there is a need for an apparatus which addresses one or more of the above identified inadequacies.